1. Field of the Invention
The present invention relates to a removable integrated circuit card that is inserted into electronic apparatus in order to connect with integrated circuit elements within the card.
2. Description Relative to the Prior Art
An integrated circuit card encloses one or more integrated circuit elements mounted on a substrate and connected to an electrical contact pattern toward one end of the card. A shutter is provided to cover and protect the contact pattern when the card is removed from an electrical connector in the electronic apparatus and to expose the contact pattern for electrical connection when the card is inserted into the connector. Moreover, it is desirable to provide a card configuration that prevents wrong-way insertion and consequential damage to the card and/or its contact pattern.
It is known to combine the operation of one-way insertion and shutter opening by means of one member located in the electrical connector that receives the card. For example, in U.S. Pat. No. 4,695,925 the connector includes a pair of opening pins that enter holes in a forward area of the card, thereby contacting the shutter and urging the shutter open. The pins (and the holes therewith) may be unsymmetrically positioned with respect to the card to prevent wrong-way insertion. In U.S. Pat. No. 4,780,793, shutter-opening ridges formed in the connector are keyed to grooves in the card to prevent a wrong-way insertion. However, in each case, the card must be fully, or almost fully, inserted before wrong-way insertion can be detected because the shutter opening pins or the grooves act upon the forward-most area of the card. This is a problem with respect to a typical situation because the user, upon encountering some reluctance toward the end of a card's travel, might be inclined to jam the card further into the apparatus. This is of particular concern since a wrong-way obstruction might easily be mistaken for the force that must be overcome in order to initiate travel of the shutter. It is consequently desirable to provide a wrong-way warning earlier in the card's travel so that there is no mistaking its meaning.
An early-warning provision is seen in U.S. Pat. No. 4,878,139 in connection with a loading apparatus for a floppy disk. The cartridge has an oblique edge at a forward corner which pushes a rearwardly-located slide pin out of the way when correctly inserted. When the cartridge is inserted on the wrong side, a square corner of the cartridge collides with the pin and prevents further advance. Shutter opening is handled by a separate mechanism. On the other hand, having the wrong-way detection mechanism also open the shutter (as in U.S. Pat. Nos. 4,695,925 and 4,780,793) helps to reduce parts and complexity. By separating the functions, that is, by enabling wrong-way detection well before shutter opening, completely separate members would appear to be necessary.